A centrifugal circulation pump for a fluid heat carrier where the pump has a housing including a centrifugal impeller, an inlet pipe for admitting a first heat carrier into the housing and a discharge pipe for discharging the first heat carrier from the housing. A heat transfer means in the form of a tubular coil is positioned in the housing through which a second heat carrier flows. The centrifugal impeller moves the first heat carrier with a swirl motion in a direction parallel to the turns of the coil whereby heat is exchanged between the first and second heat carriers.
